I was looking into adding sync signal capabilities to my CEVS app to mimic what KORG have in their SyncKontrol app for iOS. Their app generates an audio pulse which can be used to control tempo on Monotribe and Volca machines. Adding it to CEVS would mean people on all platforms could benefit from the extra control as well as adding swing capabilities to machines without a swing knob such as the Volca Keys, Bass, etc.

The Volca Sample does have a swing knob but many have noticed that it doesn't seem to send its swing signal via the "sync out" jack unfortunately. The following post is the result of my research into KORG' s sync signal and explains why other Volcas just can't swing like the Sample. If someone from KORG wants to chime in and correct or confirm my findings (paging Takahashi-san) , that would be awesome.

Open the following image to follow along. It might look a bit technical but I'll do my best to keep to simple terms.

Figure 1 shows KORG's basic sync clock in pink. A clock signal is just that, a reliable voltage pulse either from the machine itself or from another source that comes around on time, regularly, like seconds on a clock. Synths "listen in" on this signal to sync up their sequencers, LFOs, etc. Below that are 16 step boxes which represent the steps on a Volca machine. Notice how they appear at regular intervals. This is because their timing relies on the sync clock.

The first thing to notice is that the clock skips a 16th note step, it actually lines up with 8th note timing instead. This is very important and the main reason why we're seeing some strange things between machines. Having a clock that runs slower than your smallest step isn't a big deal, electronics can easily work out sub-step timing as soon as they receive 2 pulses. The problem comes when you want to create effects like swing.

Swing (sometimes called shuffle) is the change in timing from a straight, evenly-spaced sequence. It's often used to create more human, less-mechanical rhythms. An example in nature would be the human heart. It doesn't go BOOM-BOOM-BOOM, it goes, BOOOM-baBOOOM-baBOOOM due to the timing of the various squishy valves in there. In musical notation, this is often represented by dotted notes. One note is held a bit longer, at the expense of the next note which comes in a bit later and gets shortened by an equivalent amount.

The size of the note we chose to stretch is what defines the type of swing. If we use 8th notes as our measure of the "note", and then play fast (16ths) notes we get a swinging effect that sounds more rigid, like a military snare march. If we use 16th notes as the swing unit of measure, we get a more groovy "house / hiphop" sound. (see audio examples at the bottom of this post)

Looking at Figure 2, you'll see how the SyncKontrol app creates swing by delaying every other 8th note pulse. The timing delay is defined by the swing amount in the app and goes from barely noticeable to extreme where the second note has barely started before the next comes in again. When we apply this to a machine with a 16-step sequencer, we see that the two first steps are longer and the second two are shorter and delayed. This is because we're essentially splitting our swung 8th notes into halves to get our 16ths note steps.

Now in Figure 3, we see how the Volca Sample does its own thing and (I presume) modifies the sub-divided internal clock of higher precision to control swing when you turn the physical knob on the unit. The swing modifies every second 16th note this time (dark red clock), giving us the nicer swing effect. When it comes time to generate a sync signal for the Sync Out jack, it uses every other clock pulse in order to create a compatible signal to the standard already established. (pink clock). You'll notice how those pulses aren't affected by the Sample's swing, which is why we perceive the Sample to not send its swing across to others.

Conclusion: Apart from working with hacks like working in double-time (and spreading out your beats over 2 parts), the other machines simple will never be able to swing like the Volca Sample. The timing protocol is established to 8ths notes and changing that in the future would mean old machines would play twice as fast. Why KORG chose this is a mystery, seems odd given that most synths since forever have relied on 16-step sequencers... Maybe a decision was made in the name of simplifying things for low-cost machines, maybe it was historical reasons to be compatible with even older machines (I'll admit I'm pretty new to hardware synths). Maybe an oversight with regards to ever offering swing in the first place. But hey, at least knowing why helps quell the frustration, right?

And to answer a question which I'm sure will come up: Yes, I'll be adding my "SyncKontrol" module to CEVS anyway. Just don't expect miracles from it.

Here are some audio examples to help explain the difference between no swing, 8th note swing and 16th note swing (same beat used, created in Caustic, shuffle set to 50%)

As an interesting side-note: What happens if you send a swung synckontrol signal to a Volca Sample that's got its swing knob turned up? A multiplied result which sounds really weird. Every step in a 4-step sequence starts long and gets shorter and shorter. I'll save you the graph this time but you can try for yourself.

Forums:

In this tutorial, I show how to record and loop simple acoustic guitar parts with Caustic's PCM Synth. The process works for any type of instrument/vocals/whatever that you want to include alongside your Caustic synth and drum tracks.

It's not like recording audio in a multi-track DAW. Your don't record into a timeline, you simply record parts "live" as you play along to your Caustic project. You then edit the audio - and loop it if you want to - with PCM Synth and assign each recording to it's own key on the keyboard.

KORG were nice enough to open up their volca sample SDK to 3rd parties so I took a few days to rip out Caustic's WAV editor and turn it into a stand-alone, multi-platform tool that lets you import, load, record, edit and upload samples for use with your KORG Volca Sample device. It was taken from my Caustic 3.2 working branch, so it even has a few more functions than what's in Caustic 3.1!

Features:

- Record your own samples using your device's built-in microphone.
- Load any uncompressed, mono or stereo WAV, at any sampling rate or bit depth.
- Apply any of 16 of Caustic's effects and preview them in real-time, then stamp down and apply more.
- Process waveform audio with Fade In/Out, Normalize, Amplify, Reverse, etc.
- Use Caustic's C-SFXR to generate retro video game sounds.
- Trim audio precisely, down to individual samples.
- View the frequency spectrum of your audio.

This is not an official KORG app, it is made by me, Rej Poirier / SingleCellSoftware using the KORG volca sample SDK.

The app is free, with no ads and no IAPs. If you'd like to support my work, please buy Caustic or any other of my apps. If you have them all... make a donation to the Red Cross. There are people out there who need the money more than I do this holiday season.

Although it didn't happen as fast as I would have hoped, the Caustic 3.1 update is live. This update brings the much requested AudioBus and virtual MIDI support for iOS as well as a brand new synth, machine routing, velocity drum pads, undo/redo, UI skins, stability improvements and much more.

Check out the "what's new video" for a quick look at the new stuff. And be sure to watch all the other new videos too...

Contrary to Caustic, LoopStack never really worked on Windows because I couldn't be bothered to hook up the microphone code. A couple of people asked for it , so a few months back I hooked it all up and made a release package.

Yesterday someone requested Sand! for Windows, and even though there are tons of better alternatives for Windows, I'm happy to release that too.

Same as Caustic, the Windows versions are not officially supported so use them if they work for you, but please don't request support for them.

If you're looking for some vocal clips to spice up your Caustic tracks but you don't want to use your own voice, forum member Bojeroo a.k.a. PolynomialC Software has you covered with his newly released Vocality app for Android.

Vocality is a front-end tool for whatever text-to-speech engine(s) you have on your device. It provides a simple interface for entering text, changing speed and pitch and previewing it all in real-time. Once you're satisfied with the clip, you can save it as a WAV File for use in Caustic or any other software you have that accepts WAV files. I'll be working closely with Bojeroo to streamline the workflow of getting Vocality clips into Caustic in the future.

I've been playing with it and installing various TTS engines from the play store this morning. I definitely recommend the Ivona voices, you can try them on their website and download the one(s) you want to your Android device (not all their PC voices are available). They seem to be in beta right now so all the voices are free during this period.

If you're wondering what it sounds like, well try the app for yourself (it's free!), but have a listen at a recent Caustic track from forum member Danjdob. Vocality loaded with one of Ivona's female voices was used to create the two spoken samples in the track ("the power is in the music, the music is in the soul")